Inbred corn line NPXO5745GT21

ABSTRACT

Basically, this invention provides for an inbred corn line designated NPXO5745GT21, methods for producing a corn plant by crossing plants of the inbred line NPXO5745GT21, with plants of another corn plant. The invention relates to the various parts of inbred NPXO5745GT21, including culturable cells. This invention also relates to methods for introducing transgenic transgenes into inbred corn line NPXO5745GT21, and plants produced by these methods.

FIELD OF THE INVENTION

This invention is in the field of corn breeding. The invention relates to a maize and its seed designated NPXO5745GT21, derivatives and hybrids thereof. This invention also is in the field of hybrid maize production employing the present inbred.

BACKGROUND OF THE INVENTION

Corn plants (Zea mays L.) can be self-pollinating or cross pollinating. Self pollination for extended time periods produces homozygousity at almost all gene loci, forming a uniform population of true breeding progeny. These are inbreds. Crossing two homozygous inbreds produces heterozygous gene loci in hybrid plants and seeds.

Maize plant breeding is a process to develop improved maize germplasm in an inbred or hybrid. Hybrids are developed with inbreds which are developed by selecting corn lines and self pollinating these lines for several generations to develop homozygous pure inbred lines. Two inbred lines are crossed and hybrid seed is produced. One inbred is emasculated and the pollen from the other inbred pollinates the emasculated inbred. The emasculated inbred, often referred to as the female, produces the hybrid seed F1. Emasculation of the inbred can be done by detasseling the seed parent, or the inbred could have a male sterility factor which would eliminate the need to detassel the inbred.

Whether the seed producing plant is emasculated due to detasseling or CMS or transgenes, the seed produced by crossing two inbreds in this manner is hybrid seed. This hybrid seed is F1 hybrid seed. The grain produced by a plant grown from a F1 hybrid seed is referred to as F2 or grain. Although, all F1 seed and plants, produced by this hybrid seed production system using the same two inbreds should be substantially the same, all F2 grain produced from the F1 plant will be segregating maize material.

The hybrid seed production produces hybrid seed which is heterozygous. The heterozygosis results in hybrid plants, which are robust and vigorous plants. Inbreds on the other hand are mostly homozygous. This homozygosity renders the inbred lines less vigorous. Inbred seed can be difficult to produce since the inbreeding process in corn lines decreases the vigor. However, when two inbred lines are crossed, the hybrid plant evidences greatly increased vigor and seed yield compared to open pollinated, segregating maize plants. An important consequence of the homozygosity and the homogenity of the inbred maize lines is that all hybrid seed produced from any cross of two such elite lines will be the same hybrid seed and make the same hybrid plant. Thus the use of inbreds makes hybrid seed which can be reproduced readily.

The ultimate objective of the commercial maize seed companies is to produce high yielding, agronomically sound plants that perform well in certain regions or areas of the Corn Belt.

SUMMARY OF THE INVENTION

The present invention relates to an inbred corn line NPXO5745GT21. Specifically, this invention relates to plants and seeds of this line. Additionally, this relates to a method of producing from this inbred, hybrid seed corn and hybrid plants with seeds from such hybrid seed. More particularly, this invention relates to the unique combination of traits that combine in corn line NPXO5745GT21.

Generally then, broadly the present invention includes an inbred corn seed designated NPXO5745GT21. This seed produces a corn plant.

The invention also includes the tissue culture of regenerable cells of NPXO5745GT21, wherein the cells of the tissue culture regenerates plants capable of expressing the genotype of NPXO5745GT21. The tissue culture is selected from the group consisting of leaf, pollen, embryo, root, root tip, guard cell, ovule, seed, anther, silk, flower, kernel, ear, cob, husk and stalk, cell and protoplast thereof. The corn plant regenerated from NPXO5745GT21 or any part thereof is included in the present invention. The present invention includes regenerated corn plants that are capable of expressing NPXO5745GT21's genotype, phenotype or mutants or variants thereof.

The invention extends to hybrid seed produced by planting, in pollinating proximity which includes using preserved maize pollen as explained in U.S. Pat. No. 5,596,838 to Greaves, seeds of corn inbred lines NPXO5745GT21 and another inbred line if preserved pollen is not used; cultivating corn plants resulting from said planting; preventing pollen production by the plants of one of the inbred lines if two are employed; allowing cross pollination to occur between said inbred lines; and harvesting seeds produced on plants of the selected inbred. The hybrid seed produced by hybrid combination of plants of inbred corn seed designated NPXO5745GT21 and plants of another inbred line are a part of the present invention. This inventions scope covers hybrid plants and the plant parts including the grain and pollen grown from this hybrid seed.

The invention further includes a method of hybrid F1 production. A first generation (F1) hybrid corn plant produced by the process of planting seeds of corn inbred line NPXO5745GT21; cultivating corn plants resulting from said planting; permitting pollen from another inbred line to cross pollinate inbred line NPXO5745GT21; harvesting seeds produced on plants of the inbred; and growing a harvested seed are part of the method of this invention.

The present invention also encompasses a method of introducing at least one targeted trait into maize inbred line comprising the steps of: (a) crossing plant grown from the present invention seed which is the recurrent parent, representative seed of which has been deposited, with the donor plant of another maize line that comprises at least one target trait selected from the group consisting of male sterility, herbicide resistance, insect resistance, disease resistance, amylose starch, and waxy starch to produce F1 plants; (b) selecting from the F1 plants that have at least one of the targeted traits, forming a pool of progeny plants with the targeted trait; (c) crossing the pool of progeny plants with the present invention which is the recurrent parent to produce backcrossed progeny plants with the targeted trait; (d) selecting for backcrossed progeny plants that have at least one of the target traits and physiological and morphological characteristics of maize inbred line of the recurrent parent, listed in Table 1 forming a pool of selected backcrossed progeny plants; and (e) crossing the selected backcrossed progeny plants to the recurrent parent and selecting from the resulting plants for the targeted trait and physiological and morphological characteristics of maize inbred line of the recurrent parent, listed in Table 1 and reselecting from the pool of resulting plants and repeating the crossing to the recurrent parent and selecting step in succession to form a plant that comprises the desired trait and all of the physiological and morphological characteristics of maize inbred line of the recurrent parent in the present invention listed in Table 1 as determined at the 5% significance level when grown in the same environmental conditions.

This method and the following method of introducing traits can be done with less back crossing events if the trait and/or the genotype of the present invention are selected for or identified through the use of markers. SSR, microsatellites, SNP and the like decrease the amount of breeding time required to locate a line with the desired trait or traits and the characteristics of the present invention. Backcrossing in two or even three traits (for example the glyphosate, Europe corn borer, corn rootworm resistant genes) is routinely done with the use of marker assisted breeding techniques. This introduction of transgenes or mutations into a maize line is often called single gene conversion. Although, presently more than one gene particularly transgenes or mutations which are readily tracked with markers can be moved during the same “single gene conversion” process, resulting in a line with the addition of more targeted traits than just the one, but still having the characteristics of the present invention plus those characteristics added by the targeted traits.

The method of introducing a desired trait into maize inbred line comprising: (a) crossing plant grown from the present invention seed, representative seed of which has been deposited the recurrent parent, with plant of another maize line that comprises at least one target trait selected from the group consisting of nucleic acid encoding an enzyme selected from the group consisting of phytase, stearyl-ACP desaturase, fructosyltransferase, levansucrase, amylase, invertase and starch branching enzyme, the donor parent to produce F1 plants; (b) selecting for the targeted trait from the F1 plants, forming a pool of progeny plants; (c) crossing the progeny plants with the recurrent parent to produce backcrossed progeny plants; (d) selecting for backcrossed progeny plants that have at least one of the target trait and physiological and morphological characteristics of maize inbred line of the present invention as listed in Table 1 forming a pool of backcrossed progeny plants; and repeating a step of crossing the new pool with the recurrent parent and selecting for the targeted trait and the recurrent parents characteristics until the selected plant is essentially the recurrent parent with the targeted trait or targeted traits. This selection and crossing may take at least 4 backcrosses if marker assisted breeding is not employed.

The inbred line and seed of the present invention are employed to carry the agronomic package into the hybrid. Additionally, the inbred line is often carrying transgenes that are introduced in to the hybrid seed.

Likewise included is a first generation (F1) hybrid corn plant produced by the process of planting seeds of corn inbred line NPXO5745GT21; cultivating corn plants resulting from said planting; permitting pollen from inbred line NPXO5745GT21 to cross pollinate another inbred line; harvesting seeds produced on plants of the inbred; and growing a plant from such a harvested seed.

A number of different techniques exist which are designed to avoid detasseling in maize hybrid production. Some examples are switchable male sterility, lethal genes in the pollen or anther, inducible male sterility, male sterility genes with chemical restorers. There are numerous patented means of improving upon the hybrid production system. Some examples include U.S. Pat. No. 6,025,546, which relates to the use of tapetum-specific promoters and the barnase gene to produce male sterility; U.S. Pat. No. 6,627,799 relates to modifying stamen cells to provide male sterility. Therefore, one aspect of the current invention concerns the present invention comprising one or more gene(s) capable of restoring male fertility to male-sterile maize inbreds or hybrids and/or genes or traits to produce male sterility in maize inbreds or hybrids.

The inbred corn line NPXO5745GT21 and at least one transgenic gene adapted to give NPXO5745GT21 additional and/or altered phenotypic traits are within the scope of the invention. Such transgenes are usually associated with regulatory elements (promoters, enhancers, terminators and the like). Presently, transgenes provide the invention with traits such as insect resistance, herbicide resistance, disease resistance increased or decreased starch or sugars or oils, increased or decreased life cycle or other altered trait.

The present invention includes inbred corn line NPXO5745GT21 and at least one transgenic gene adapted to give NPXO5745GT21 modified starch traits. Furthermore this invention includes the inbred corn line NPXO5745GT21 and at least one mutant gene adapted to give modified starch, acid or oil traits, i.e. amylase, waxy, amylose extender or amylose. The present invention includes the inbred corn line NPXO5745GT21 and at least one transgenic gene: bacillus thuringiensis, the bar or pat gene encoding phosphinothricin acetyl transferase, Gdha gene, GOX, VIP, EPSP synthase gene, low phytic acid producing gene, and zein. The inbred corn line NPXO5745GT21 and at least one transgenic gene useful as a selectable marker or a screenable marker is covered by the present invention.

A tissue culture of the regenerable cells of hybrid plants produced with use of NPXO5745GT21 genetic material is covered by this invention. A tissue culture of the regenerable cells of the corn plant produced by the method described above is also included.

DEFINITIONS

In the description and examples, which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specifications and claims, including the scope to be given such terms, the following definitions are provided.

ALLELE—Any alternative forms of sequence. Diploid cells carry two alleles of the genetic sequence. These two sequence alleles correspond to the same locus (i.e. position) on homologous chromosomes.

ELITE INBRED—Maize plant that is substantially homozygous and which contributes useful agronomic and/or phenotypic qualities when used to produce hybrids that are commercially acceptable.

GENE SILENCING—The loss or inhibition of the expression of a gene.

GENOTYPE—genetic makeup.

LINKAGE—Refers to a tendency of a segment of DNA on the same chromosome to not separate during meiosis of homologous chromosomes. Thus during meiosis this segment of DNA remains unbroken more often than expected by chance.

LINKAGE DISEQUILIBRIUM—Alleles tendency to remain in linked groups when segregating from parents to progeny, than expected from chance.

LOCUS—A defined segment of DNA. This segment is often associated with an allele position on a chromosome.

PHENOTYPE—The detectible characteristics of the maize plant. These characteristics often are detections of the genotype/environment interaction.

PLANT—this includes reference to an immature or mature whole plant, including a plant that has been detasseled or from which seed or grain has been removed. Seed or embryo that will produce the plant is also considered to be the plant.

Early Season Trait Codes

Emergence Rating (EMRGR): Recorded when 50% of the plots in the trial are at V1 (1 leaf collar) growth stage.

-   -   1=All plants have emerged and are uniform in size     -   3=All plants have emerged but are not completely uniform     -   5=Most plants have emerged with some just beginning to break the         soil surface, noticeable lack of uniformity     -   7=Less than 50% of the plants have emerged, and lack of         uniformity is very noticeable     -   9=A few plants have emerged but most remain under the soil         surface.         Seedling Growth (SVGRR or Vigor): Recorded between V3 and V5         (3-5 leaf stage) giving greatest weight to seedling plant size         and secondary weight to uniform growth.     -   1=Large plant size and uniform growth     -   3=Acceptable plant size and uniform growth     -   5=Acceptable plant size and might be a little non-uniform     -   7=Weak looking plants and non-uniform growth     -   9=Small plants with poor uniformity         Purpling (PRPLR): Emergence and/or early growth rating. Purpling         is more pronounced on the under sides of leaf blades especially         on midribs.     -   1=No plants showing purple color     -   3=30% plants showing purple color     -   5=50% plants showing purple color     -   7=70% plants showing purple color     -   9=90+% plants showing purple color         Herbicide Injury (HRBDR) List the herbicide type, which is being         rated. Then rated each hybrid/variety injury as indicated below.     -   1=No apparent reduction in biomass or other injury symptoms     -   5=Moderate reduction in biomass with some signs of sensitivity     -   9=Severe reduction in biomass with some mortality         Mid-Season Traits Codes         Heat Units to 50% Silk (HUPSN): Recorded the day when 50% of all         plants within a plot show 2 cm or more silk protruding from the         ear. Converted days to accumulated heat units from planting.         Heat units to 50% Pollen Shed (HUPSN): Recorded the day when 50%         of all plants within a plot are shedding pollen. Converted days         to accumulated heat units from planting.         Plant Height (PLHTN): After pollination, recorded average plant         height of each plot. Measured from ground to base of leaf noted.         Plant Ear Height (ERHTN): After pollination record average ear         height of each plot. Measure from ground to base of ear node         (shank). —for Inbreds         Plant Ear Height in CM: After pollination record average ear         height of each plot. Measure from ground to base of ear node         (shank). —for Hybrids         Root Lodging Early % (ERTLP): Early root lodging occurs up to         about two weeks after flowering and usually involves         goosenecking. The number of root lodged plants are counted and         converted to percentage.         Shed Duration (Shed Duration): Sum of daily heatunits for days         when plants in the plot are actively shedding pollen.         Foliar Disease (LFDSR): Foliar disease ratings taken one month         before harvest through harvest. The predominant disease should         be listed in the trial information and individual hybrid ratings         should be given.     -   1=No lesions to two lesions per leaf.     -   3=A few scattered lesions on the leaf. About five to ten percent         of the leaf surface is affected.     -   5=A moderate number of lesions are on the leaf. About 15 to 20         percent of the leaf surface is affected.     -   7=Abundant lesions are on the leaf. About 30 to 40 percent of         the leaf surface is affected.     -   9=Highly abundant lesions (>50 percent) on the leaf. Lesions are         highly coalesced. Plants may be prematurely killed.         Data collection (as described above) on the following diseases:

Common Rust (CR) Eye Spot (ES) Gray Leaf Spot (GLS) Northern Corn Leaf Blight (NCLB) Stewart's Bacterial Wilt (SBW) Southern Corn Leaf Blight (SCLB) Southern Rust (SR) Corn Virus Complex (CVC) Maize response to diseases can also be rated as:

-   -   R=Resistant=1 to 2 rating     -   MR=Moderately Resistant=3 to 4 rating     -   MS=Moderately Susceptible=5 to 6 rating     -   S=Susceptible=7 to 9 rating         PREHARVEST TRAIT CODES         Heat units to Black Layer (HUBLN): The day when 50% of all         plants within a plot reach black layer stage is recorded.         Convert days to accumulated heat units from planting.         Harvest Population (HAVPN): The number of plants in yield rows,         excluding tillers, in each plot are counted.         Barren Plants (BRRNP): The number of plants in yield rows having         no ears and/or abnormal ears with less than 50 kernels are         counted.         Dropped Ears (DROPP): The numbers of ears lying on the ground in         yield rows are counted.         Stalk Lodging % (STKLP): Stalk lodging will be reported as         number of plants broken below the ear without pushing, excluding         green snapped plants. The number of broken plants in yield rows         are counted and converted to percent.         Root Lodging Late % (LRTLP): Late root lodging can usually start         to occur about two weeks after flowering and involves lodging at         the base of the plant. Plants leaning at a 30-degree angle or         more from the vertical are considered lodged. The number of root         lodged plants in yield rows are counted and converted to         percent.         Push Test for Stalk and Root Quality on Erect Plants % (PSTSP or         PCT Push or % Pushtest): The push test is applied to trials with         approximately five percent or less average stalk lodging. Plants         are pushed that are not root lodged or broken prior to the push         test. Standing next to the plant, the hand is placed at the top         ear and pushed to arm's length. Push one of the border rows         (four-row small plot) into an adjacent plot border row. The         number of plants leaning at a 30-degree angle or more from the         vertical, including plants with broken stalks prior to pushing         are counted. Plants that have strong rinds that snap rather than         bend over easily are not counted. The goal of the push test is         to identify stalk rot and stalk lodging potential, NOT ECB         injury.         PUSXN: Push ten plants and enter the number of plants that do         not remain upright.         Intactness (INTLR):     -   1=Healthy appearance, tops unbroken     -   5=25% of tops broken     -   9=majority of tops broken         Plant Appearance (PLTAR): This is a visual rating based on         general plant appearance taking into account all factors of         intactness, pest, and disease pressure.     -   1=Complete plant with healthy appearance     -   5=plants look OK     -   9=Plants not acceptable         Green Snap (GRSNP or PCTGS or % GreenSnap): Counted the number         of plants in yield rows that snapped below the ear due to         brittleness associated with high winds.         Stay-green (STGRP): This is an assessment of the ability of a         grain hybrid to retain green color as maturity approaches (taken         near the time of black-layer) and should not be a reflection of         hybrid maturity or leaf disease. Recorded % of green tissue.         This may be listed as a Stay Green Rating instead of a         Percentage.         Stay Green Rating (STGRR): This is an assessment of the ability         of a grain hybrid to retain green color as maturity approached         (taken near the time of black layer or if major differences are         noted later). This rating should not be a reflection of the         hybrid maturity or leaf disease.     -   1=solid Green Plant     -   9=no green tissue         Ear/Kernel Rots (KRDSR): If ear or kernel rots are present, husk         ten consecutive ears in each plot and count the number that have         evidence of ear or kernel rots, multiply by 10, and round up to         the nearest rating as described below. Identify and record the         disease primarily responsible for the rot.     -   1=No rots, 0% of the ears infected.     -   3=Up to 10% of the ears infected.     -   5=11 to 20% of the ears infected.     -   7=21 to 35% of the ears infected.     -   9=36% or more of the ears infected.         Grain Quality (GRQUR): Taken on husked ears after black layer         stage. The kernel cap integrity and relative amount of soft         starch endosperm along the sides of kernels is rated.     -   1=smooth kernel caps and or 10% or less soft starch     -   3=slight kernel wrinkles and or 30% soft starch     -   7=moderate kernel wrinkles and or 70% soft starch     -   9=severe kernel wrinkled and or 90% or more soft starch         Preharvest Hybrid Characteristics         Ear Shape (DESHR): Slender, Semi-Blocky, Blocky     -   1=Blocky     -   5=Semi-blocky     -   9=Slender         Ear Type (EARFR): Fixed, Semi-Fixed, Flex     -   1=Flex     -   5=Semi-flex     -   9=Fixed         Husk Cover (HSKCR): Short, Medium, Long     -   1=Long     -   5=Medium     -   9=Short         Kernel Depth (KRLNR): Shallow, Medium, Deep     -   1=Deep     -   5=Medium     -   9=Short (shallow)         Shank Length (SHLNR): Short, Medium, Long     -   1=Short     -   5=Medium     -   9=Long         Kernel Row Number (KRRWN): The average number of kernel rows on         3 ears.         Cob diameter (COBDR): Cob diameter is to be taken with template.     -   1: small     -   5: Medium     -   9: Large         Harvest Trait Codes         Number of Rows Harvested (NRHAN)         Plot Width (RWIDN)         Plot Length (RLENN)         Yield Lb/Plot (YGSMN): bushels per acre adjusted to 15.5%         moisture         Test Weight (TSTWN or TWT): test weight at harvest in pounds per         bushel         Moisture % (MST_P): percent moisture or grain at harvest         Adjusted Yield in Bu/A (YBUAN)         Color Codes         Kernel Type: (KRTPN)     -   1) Dent     -   2) Flint         Endosperm Type: (KRTEN)     -   1) normal     -   2) amylose     -   3) waxy     -   4) other         Sterile Type (MSCT):     -   1) no     -   if yes cytoplasm type then:     -   2) c-type     -   3) s-type         Anthocyanin of Brace Roots (PBRCC): the presence of color on 60%         of the brace roots during pollen shed.     -   1) Absent     -   2) Faint     -   3) Moderate     -   4) Dark     -   5) Brace Roots not present     -   6) Green     -   7) Red     -   8) Purple         Anther Color (ANTCC): at 50 percent pollen shed observe the         color of newly extruded anthers, pollen not yet shed     -   1) Yellow     -   2) Red     -   3) Pink     -   4) Purple         Glume Color (GLMCC): color of glumes prior to pollen shed     -   1) Red     -   2) Green         Silk Color (SLKCC): Taken at a late flowering stage when all         plants have fully extruded silk. Silks at least 2″ long but         still fresh.     -   1) Yellow     -   2) Pink     -   3) Red         Kernel Color (KERCC): the main color of the kernel from at least         three ears per ear family.     -   1) Yellow     -   2) White         Cob Color (COBCC): the main color of the cob after shelling from         at least three ears per ear family.     -   1) Red     -   2) Pink     -   3) White

Input ABR. Description Value EMRGN Final number of plants per plot # REGNN Region Developed: 1. Northwest 2. Northcentral # 3. Northeast 4. Southeast 5. Southcentral 6. Southwest 7. Other CRTYN Cross type: 1. sc 2. dc 3. 3w 4. msc 5. m3w # 6. inbred 7. rel. line 8. other KRTPN Kernel type: 1. sweet 2. dent 3. flint 4. flour 5. pop 6. ornamental 7. pipecorn 8.other # EMERN Days to Emergence EMERN # Days ERTLP % Root lodging: (before anthesis): # % GRSNP % Brittle snapping: (before anthesis): # % TBANN Tassel branch angle of 2nd primary lateral degree branch (at anthesis): HUPSN Heat units to 50% pollen shed: (from emergence) # HU SLKCN Silk color: #/Munsell value HU5SN Heat units to 50% silk: (from emergence) # HU DSAZN Days to 50% silk in adapted zone: # Days HU9PN Heat units to 90% pollen shed: (from emergence) # HU HU19N Heat units from 10% to 90% pollen shed: # HU DA19N Days from 10% to 90% pollen shed: # Days LSPUR Leaf sheath pubescence of second leaf above # the ear (at anthesis) 1-9 (1 = none): ANGBN Angle between stalk and 2nd leaf above the ear degree (at anthesis): CR2LN Color of 2nd leaf above the ear (at anthesis): #/Munsell value GLCRN Glume Color: #/Munsell value GLCBN Glume color bars perpendicular to their veins # (glume bands): 1. absent 2. present ANTCN Anther color: #/Munsell value PLQUR Pollen Shed: 1-9 (0 = male sterile) # HU1PN Heat units to 10% pollen shed: (from emergence) # HU LAERN Number of leaves above the top ear node: # LTBRN Number of lateral tassel branches that originate # from the central spike: EARPN Number of ears per stalk: # APBRR Anthocyanin pigment of brace roots: 1.absent # 2.faint 3.moderate 4.dark TILLN Number of tillers: # HSKCN Husk color 25 days after 50% silk: (fresh) #/Munsell value MLWVR Leaf marginal waves: 1-9 (1 = none) # LFLCR Leaf longitudinal creases: 1-9 (1 = none) # ERLLN Length of ear leaf at the top ear node: # cm ERLWN Width of ear leaf at the top ear node at the # cm widest point: PLHTN Plant height to tassel tip: # cm ERHCN Plant height to the top ear node: # cm LTEIN Length of the internode between the ear node # cm and the node above: LTASN Length of the tassel from top leaf collar to tassel # cm tip: HSKDN Husk color 65 days after 50% silk: (dry) #/Munsell value DSGMN Days from 50% silk to 25% grain moisture in # Days adapted zone: SHLNN Shank length: # cm ERLNN Ear length: # cm ERDIN Diameter of the ear at the midpoint: # mm EWGTN Weight of a husked ear: # gm KRRWR Kernel rows: 1. indistinct 2. distinct # KRNAR Kernel row alignment: 1. straight 2. slightly curved # 3. curved ETAPR Ear taper: 1. slight 2. average 3. extreme # KRRWN Number of kernel rows: # COBCN Cob color: #/Munsell value HSKTR Husk tightness 65 days after 50% silk: 1-9 # (1 = loose) COBDN Diameter of the cob at the midpoint: # mm YBUAN Yield: # kg/ha KRTEN Endosperm type: 1. sweet 2. extra sweet 3. normal 3 4. high amylose 5. waxy 6. high protein 7. high lysine 8. super sweet 9. high oil 10. other KRCLN Hard endosperm color: #/Munsell value ALECN Aleurone color: #/Munsell value ALCPR Aleurone color pattern: 1. homozygous # 2. segregating KRLNN Kernel length: # mm KRWDN Kernel width: # mm KRDPN Kernel thickness: # mm K1KHN 100 kernel weight: # gm HSKCR Husk extension: 1. short (ear exposed) 2. medium # (8 cm) 3. long (8-10 cm) 4. very long (>10 cm) KRPRN % round kernels on 13/64 slotted screen: # % HEPSR Position of ear 65 days after 50% silk: 1. upright # 2. horizontal 3. pendent STGRP Staygreen 65 days after anthesis: 1-9 (1 = worst) # DPOPP % dropped ears 65 days after anthesis: % LRTRP % root lodging 65 days after anthesis: % HU25N Heat units to 25% grain moisture: (from # HU emergence) HUSGN Heat units from 50% silk to 25% grain moisture in # HU adapted zone:

DETAILED DESCRIPTION OF THE INVENTION

The inbred provides uniformity and stability within the limits of environmental influence for traits as described in the Variety Description Information (Table 1) that follows.

Male sterility and/or CMS systems for maize parallel the CMS type systems that have been routinely used in hybrid production in sunflower. Male sterility can be accomplished by transgenes, by chemicals, by a mixture of transgenes, natural or induced sterility mutations, and/or chemicals.

To produce hybrids, the companies must develop inbreds, which carry needed traits into the hybrid combination. Hybrids are not often uniformly adapted for the entire Corn Belt, but most often are specifically adapted for regions of the Corn Belt. Northern regions of the Corn Belt require shorter season hybrids than do southern regions of the Corn Belt. Hybrids that grow well in Colorado and Nebraska soils may not flourish in richer Illinois and Iowa soils. Thus, a variety of major agronomic traits is important in hybrid combination for the various Corn Belt regions, and has an impact on hybrid performance.

Inbred line development and hybrid testing have been emphasized in the past half-century in commercial maize production as a means to increase hybrid performance. Inbred development can be by pedigree selection, haploid/doubled haploid production, and recurrent selection. Pedigree selection can be the selection in an F2 population produced from a planned cross of two genotypes (often elite inbred lines), or selection of progeny of synthetic varieties, open pollinated, composite, or backcrossed populations. This type of selection is effective for highly inheritable traits, but other traits, for example, yield requires replicated test crosses at a variety of stages for accurate selection.

Maize breeders select for a variety of traits in inbreds that impact hybrid performance along with selecting for acceptable parental traits. Such traits include but are not limited to: yield potential in hybrid combination, dry down, maturity, grain moisture at harvest, greensnap, resistance to root lodging, resistance to stalk lodging, grain quality, disease and insect resistance, ear, and plant height. Additionally, hybrid performance will differ in different soil types such as low levels of organic matter, clay, sand, black, high pH, low pH; or in different environments such as wet environments, drought environments, and no tillage conditions. These traits appear to be governed by a complex genetic system that makes selection and breeding of an inbred line extremely difficult. Even if an inbred, in hybrid combination, has excellent yield (a desired characteristic), it may not be useful because it fails to have acceptable parental traits such as seed yield, seed size, pollen production, good silks, plant height, etc.

To illustrate the difficulty of breeding and developing inbred lines, the following example is given. Two inbreds compared for similarity of 29 traits differed significantly for 18 traits between the two lines. If 18 simply inherited single gene traits were polymorphic with gene frequencies of 0.5 in the parental lines, and assuming independent segregation (as would essentially be the case if each trait resided on a different chromosome arm), then the specific combination of these traits as embodied in an inbred would only be expected to become fixed at a rate of one in 262,144 possible homozygous genetic combinations. Selection of the specific inbred combination is also influenced by the specific selection environment on many of these 18 traits which makes the probability of obtaining this one inbred even more remote. In addition, most traits in the corn genome are regrettably not single dominant genes but are multi-genetic with additive gene action not dominant gene action. Thus, the general procedure of producing a non segregating F1 generation and self pollinating to produce a F2 generation that segregates for traits and selecting progeny with the visual traits desired does not easily lead to an useful inbred. Great care and breeder expertise must be used in selection of breeding material to continue to increase yield and the agronomics of inbreds and resultant commercial hybrids.

Certain regions of the Corn Belt have specific difficulties that other regions may not have. Thus the hybrids developed from the inbreds have to have traits that overcome or at least minimize these regional growing problems. Examples of these problems include in the eastern corn belt Gray Leaf Spot, in the north cool temperatures during seedling emergence, in the Nebraska region CLN (Corn Lethal Necrosis) and in the west soil that has excessively high pH levels. The industry often targets inbreds that address these issues specifically forming niche products. However, the aim of most large seed producers is to provide a number of traits to each inbred so that the corresponding hybrid can be useful in broader regions of the Corn Belt. The new biotechnology techniques such as Microsatellites, SNPs, RFLPs, RAPDs and the like have provided breeders with additional tools to accomplish these goals.

The inbred has been produced through a doubled haploid system or is self-pollinated for a sufficient number of generations to give inbred uniformity. During plant selection in each generation, the uniformity of plant type was selected to ensure homozygosity and phenotypic stability. The line has been increased in isolated farmland environments with data on uniformity and agronomic traits being observed to assure uniformity and stability. No variant traits have been observed or are expected in NPXO5745GT21.

The best method of producing the invention is by planting the seed of NPXO5745GT21 which is substantially homozygous and self-pollinating or sib pollinating the resultant plant in an isolated environment, and harvesting the resultant seed. The hybrid seed can be produced with two inbreds, the male inbred contributing pollen to the seed and the female contributing seed but not contributing pollen to the seed.

This invention also is directed to methods for producing a corn plant by crossing a first parent corn plant with a second parent corn plant wherein the first or second parent corn plant is an inbred corn plant from the line NPXO5745GT21. Further, both first and second parent corn plants can come from the inbred corn line NPXO5745GT21 which produces a self of the inbred invention. The present invention can be employed in a variety of breeding methods which can be selected depending on the mode of reproduction, the trait, and the condition of the germplasm. Thus, any breeding methods using the inbred corn line NPXO5745GT21 are part of this invention: selfing, backcrosses, hybrid production, and crosses to populations, and haploid by such old and known methods of using KWS inducers lines, Krasnador inducers, stock six material that induces haploids and anther culturing and the like.

In the hybrid seed production using the standard CMS system there are three different maize lines required. First, there is a cytoplasmic male-sterile line usually carrying the CMS or some other form of male sterility. This line will be the seed producing parent line. Second, there must be a fertile inbred line that is the same or isogenic with the seed producing inbred parent but lacking the trait of male sterility. This is a maintainer line needed to make new inbred seed of the seed producing male sterile parent. Third there is a different inbred which is fertile, has normal cytoplasm and carries a fertility restoring gene. This line is called the restorer line in the CMS system. The CMS cytoplasm is inherited from the maternal parent (or the seed producing plant); therefore for the hybrid seed produced on such plant to be fertile the pollen used to fertilize this plant must carry the restorer gene. The positive aspect of this is that it allows hybrid seed to be produced without the need for detasseling the seed parent. However, this system does require breeding of all three types of lines: 1) male sterile-to carry the CMS, 2) the maintainer line; and, 3) the line carrying the fertility restorer gene.

In some instances, sterile hybrids are produced and the pollen necessary for the formation of grain on these hybrids is supplied by interplanting of fertile inbreds in the field with the sterile hybrids.

A number of different inventions exist which are designed to avoid detasseling in maize hybrid production. Some examples are transgenic male sterility, lethal genes in the pollen or anther, inducible or switchable male sterility, male sterility genes with chemical restorers, sterility genes linked with a promoter or color marker. U.S. Pat. No. 6,025,546, relates to the use of tapetum-specific promoters and the barnase gene. U.S. Pat. No. 6,627,799 relates to modifying stamen cells to provide male sterility. Therefore, one aspect of the current invention concerns the present invention comprising one or more gene(s) capable of producing or restoring male fertility to male-sterile maize inbreds or hybrids.

As mentioned the present invention may be useful as a male-sterile plant. Sterility can be produced by pulling or cutting tassels from the plant, detasseling, use of gametocides, or use of genetic material to render the plant sterile using a CMS type of genetic control or a nuclear genetic sterility. Male sterility is employed in a hybrid production by eliminating the pollen shed from the seed producing parent. The seed producing parent is grown in isolation from other pollen sources except for the pollen source which is the male fertile inbred, which serves as the male parent in the hybrid. To facilitate pollination of the seed producing (female) parent, the male fertile inbreds are planted most often in rows near the male sterile (female) inbred.

Methods for genetic male sterility are disclosed in EPO 89/3010153.8, WO 90/08828, U.S. Pat. Nos. 4,654,465, 4,727,219, 3,861,709, 5,432,068 and 3,710,511. Gametocides, some of which are taught in U.S. Pat. No. 4,735,649 (incorporated by reference) can be employed to make the plant male sterile. Gametocides including but not limited to glyphosate and its derivatives are chemicals or substances that negatively affect the pollen or at least the fertility of the pollen and provide male sterility to the seed producing parent.

Hybrid production employing any form of male sterility including mechanical emasculation tends to have a small occurrence of self pollinated female inbred seeds along with the intended F1 hybrid seeds. Great measures are taken to avoid the inbred seed production in a hybrid seed production field; but inbred seed unfortunately does occur in F1 seed production.

To detect inbred seed in a sample of putative hybrid seed the seeds can be tested with molecular markers, but another method is to plant the seed. The seed planting process is an inbred capture process which isolates inbred seed from hybrid F1 seed sources. This process for producing selected inbred seed comprises planting a group of seed comprising seed from a hybrid production, some of this seed may be seed of the hybrid parents. The inbred plants tend to be readily identifiable from the hybrid plants, the inbreds have a stunted appearance, i.e. shorter plant, smaller ear. Self pollination of the stunted plants grown from these identified inbred plants produces the female inbred seed or the hybrid. The resultant plants are observed for size or they can be tested by markers to identify any inbred plants. The identified inbred plants are selected and self-pollinated to form the inbred seed.

A number of well known methods can be employed to identify the genotype of maize. The ability to understand the genotype of the present invention increases as the technology moves toward better markers for identifying different components within the maize genetic material. One of the oldest methods is the use of isozymes which provides a generalized footprint of the material. Other markers adapted to provide a higher definition profile include Restriction Fragment Length Polymorphisms (RFLPs), Amplified Fragment Length Polymorphisms (AFLPs), Random Amplified Polymorphic DNAs (RAPDs), Polymerase Chain Reaction (there are different types of primers or probes) (PCR), Microsattelites (SSRs), and Single Nucleotide Polymorphisms (SNPs), sequence selection markers just to list a few. The use of these marker techniques for gathering genotype information from seeds and plants is well understood in the industry. The methods for using these techniques can be found in college textbooks such as Breeding Field Crops, Milton et. al. Iowa State University Press.

The marker profile of the inbred of this invention should be close to homozygous for alleles. A marker profile produced with any of the locus identifying systems known in the industry will identify a particular allele at a particular loci. A F1 hybrid made from the inbred of this invention will comprise a marker profile of the sum of both the profiles of its inbred parents. At each locus the allele for the present invention and the allele for the other inbred parent should be present. Thus the profile of the present invention will permit identification of hybrids as containing the inbred parent of the present invention. To identify the female portion of any hybrid the hybrid seed material from the pericarp which is maternally inherited is employed in a marker technique. The resultant profile is of the maternal parent. The comparison of this maternal profile with the hybrid profile will allow identification of the paternal profile. The present invention includes a maize cell that is part of an inbred or hybrid plant which includes its seed or plant part that has the marker profile of alleles of the present invention.

Marker systems are not just useful for identification of the present invention; they are also useful for breeding and trait conversion techniques. Polymorphisms in maize permit the use of markers for linkage analysis. If SSR are employed with flanking primers, the marker profile can be developed with PCR and Southern Blots can often be eliminated. Use of flanking markers, PCR and amplification to genotype maize matured of the material is well known by the industry. Primers for SSR markers and maize genome mapping information are publicly available through the help of the USDA at Maize GDB on the web.

Marker profiles of this invention can be employed to identify essentially derived varieties or progeny developed with the inbred in its ancestry. This inbred may have progeny identified by having a molecular marker profile with genetic contribution of the present inbred invention, as measured by either percent identity or percent similarity.

The present invention may have a new locus or trait introgressed through direct transformation, breeding methods including but not limited to backcrossing or marker assisted breeding. A backcross conversion or locus conversion both refer to a product of a backcrossing program.

The use of the present inbred as a recurrent parent in a breeding program it is often referred to as backcrossing. Backcrossing is often employed to introgression a desired trait or trait(s), either transgenic or nontransgenic, into the recurrent parent. A plant with the trait or the desired locus is crossed into recurrent maize parent usually in one or more backcrosses. If markers are employed to assist in selection of progeny that have the desired trait and recurrent parent background genetics, then the number of backcrosses needed to recover the recurrent parent with the desired trait or locus can be relatively few two or three. However, 3, 4, 5 or more backcrosses are often required to produce the desired inbred with the gene or loci conversion in place. The number of backcrosses needed for a trait introgression is often linked to the genetics of the line carrying the trait and the recurrent parent and the genetics of the trait. Multigenic traits, recessive alleles, unlinked traits play a role in the number of backcrosses that may be necessary to achieve the desired backcross conversion of the inbred.

In a book written by Hallauer entitled Corn and Corn Improvement, Sprague and Dudley, 3rd Ed. 1998 the basics of maize crossing techniques along with a number of other corn breeding methods such as recurrent, bulk or mass selection, pedigree breeding, open pollination breeding, marker assisted selection, double haploids development and selection breeding are taught. The ordinary corn breeder understands these breeding systems and how to apply such techniques to the present invention. Therefore, repetition of how to perform these breeding methods is not listed within this application.

Dominant, single gene traits or traits with obvious phenotypic changes are particularly well managed in backcrossing programs. Prior to transformation and prior to markers, backcrossing was employed since the 1950's to breed in identified maize traits.

The backcrossing program is more complicated when the trait is a recessive gene. To determine the presence of the recessive gene requires the use of some testing to determine if the trait I has been transferred. Use of markers to detect the gene reduces the complexity of trait identification in the progeny. A marker that is a SNP, specific for the trait, can increase the efficiency and speed of tracking a recessive trait within a backcrossing program. Backcrossing of recessive traits has allowed known mutation traits to be moved into more elite germplasm. Mutations can be induced in germplasm by the plant breeder. Mutations can also result from plant or seed or pollen exposure to temperature alterations, culturing, radiation in various forms, chemical mutagens like EMS and others. Some of the mutant genes which have been identified and introgressed into elite maize include the genotypes: waxy (wx), amylose extender (ae), dull (du), horny (h), shrunken (sh), brittle (bt), floury (fl), opaque (o), and sugary (su). Nomenclature for mutant genes is based on the effect these mutant genes have on the physical appearance and phenotype of the kernel. There are mutant genes which produce starch with markedly different functional properties even though the phenotypes of the seed and plant remain the same. Mutant subspecies have generally been given a number after the named genotype, for example, sugary-1 (su1), sugary-2 (su2); shrunken 1 (sh1) and shrunken 2 (sh2). Traits such as Ht, waxy, brown mid-rib, amylase, amlyose brown mid-rib, amylose extender (ae), opaque, dull, imazethapyr tolerant (IT or IR—designations for two different imazethapyr resistant genes), sterility, fertility, phytic acid, NLB, SLB, and the like have all been introgressed into elite inbreds through breeding programs. The last backcross generation is usually selfed if necessary to recover the inbred of interest with the introgressed trait.

All plants and plant cells produced using inbred corn line NPXO5745GT21 are within the scope of this invention. The invention encompasses the inbred corn line used in crosses with other, different, corn inbreds to produce (F1) corn hybrid seeds and hybrid plants and the grain produced on the hybrid plant. This invention includes plant and plant cells, which upon growth and differentiation produce corn plants having the physiological and morphological characteristics of the inbred line NPXO5745GT21.

This invention also includes transforming of introgressed transgenic genes, or specific locus into the present invention. The prior art has an extended list of transgenes, and of specific locus that carry desirable traits. The transgenes that can be introgressed include but are not limited to insect resistant genes such as Corn Rootworm gene(s) in the event DAS-59122-7, Mir604 Modified Cry3A event, Event 5307Syngenta, MON 89034, MON 88017 Bacillus thuringiensis (Cry genes) Cry34/35Ab1, Cry1A.105, PO Cry1F,_Cry2Ab2, Cry1A, Cry1AB, Cry1Ac Cry3Bb1, or herbicide resistant genes such as Pat gene or Bar gene, EPSP, the altered protoporphyrinogen oxidase (protox enzyme) U.S. Pat. Nos. 5,767,373, 6,282,837, WO 01/12825, or disease resistant genes such as the Mosaic virus resistant gene, etc., or trait altering genes such as lignin genes, flowering genes, oil modifying genes, senescence genes and the like.

The present invention also encompasses the addition of traits that focus on products or by products of the corn plant such as the sugars, oils, protein, ethanol, biomass and the like. The present invention can include a trait that forms an altered carbohydrate or altered starch. An altered carbohydrate or altered starch can be formed by an introgressed gene(s) that affect the synthase, branching enzymes, pullanases, debranching enzymes, isoamylases, alpha amylases, beta amylases, AGP, ADP and other enzymes which effect the amylose, and or amylopectin ratio or content or the branching pattern of starch. The fatty acid modifying genes if introgressed into the present invention can also affect starch content. Additionally, introgressed genes that are associated with or effect the starch and carbohydrates can be adapted so that the gene or its enzyme does not necessarily alter the form or formation of the starch or carbohydrate of the seed or plant; instead the introgressed gene or its RNA, polypeptide, protein or enzyme adapted to degrade, alter, or otherwise change the formed starch or carbohydrate. Examples of this technology are shown in U.S. Pat. Nos. 7,033,627, 5,714,474, 5,543,570, 5,705,375, 7,102,057, which are incorporated by reference. An example of use of an alpha amylase adapted in this manner in maize is shown in U.S. Pat. No. 7,407,677 which is also incorporated by reference.

The methods and techniques for inserting, or producing and/or identifying a mutation or making or reshuffling a transgene and introgressing the trait or gene into the present invention through breeding, transformation, mutating and the like are well known and understood by those of ordinary skill in the art.

Various techniques for breeding, moving or altering genetic material within or into the present invention (whether it is an inbred or in hybrid combination) are also known to those skilled in the art. These techniques to list only a few are anther culturing, haploid/double haploid production, (stock six, which is a breeding/selection method using color markers and is a method that has been in use for forty years and is well known to those with skill in the art), transformation, irradiation to produce mutations, chemical or biological mutation agents and a host of other methods are within the scope of the invention. All parts of the NPXO5745GT21 plant including its plant cells produced using the inbred corn line are within the scope of this invention. The term transgenic plant refers to plants having genetic sequences, which are introduced into the genome of a plant by a transformation method and the progeny thereof. Transformation methods are means for integrating new genetic coding sequences into the plant's genome by the incorporation of these sequences into a plant through man's assistance, but not by breeding practices. The transgene once introduced into plant material and integrated stably can be moved into other germplasm by standard breeding practices.

The recombinant DNA molecules of the invention can be introduced into the plant cell in a number of art-recognized ways. Suitable methods of transforming plant cells include microinjection (Crossway et al., BioTechniques 4:320-334 (1986)), electroporation (Riggs et al, Proc. Natl. Acad. Sci. USA 83:5602-5606 (1986)), agrobacterium mediated transformation (Hinchee et al., Biotechnology 6:915-921 (1988)), direct gene transfer (Paszkowski et al., EMBO J. 3:2717-2722 (1984)), ballistic particle acceleration using devices available from Agracetus, Inc., Madison, Wis. and Dupont, Inc., Wilmington, Del. (see, for example, Sanford et al., U.S. Pat. No. 4,945,050; and McCabe et al., Biotechnology 6:923-926 (1988)), protoplast transformation/regeneration methods (see U.S. Pat. No. 5,350,689 issued Sep. 27, 1994 to Ciba-Geigy Corp.), Whiskers technology (See U.S. Pat. Nos. 5,464,765 and 5,302,523) and pollen transformation (see U.S. Pat. No. 5,629,183). Also see, Weissinger et al., Annual Rev. Genet. 22:421-477 (1988); Sanford et al., Particulate Science and Technology 5:27-37 (1987) (onion); Christou et al., Plant Physiol. 87:671-674 (1988) (soybean); McCabe et al., Bio/Technology 6:923-926 (1988) (soybean); Datta et al., Bio/Technology 8:736-740 (1990) (rice); Klein et al., Proc. Natl. Acad. Sci. USA, 85:4305-4309 (1988) (maize); Klein et al., Bio/Technology 6:559-563 (1988) (maize); Klein et al., Plant Physiol. 91:440-444 (1988) (maize); Fromm et al., Bio/Technology 8:833-839 (1990); Gordon-Kamm et al., Plant Cell 2:603-618 (1990) (maize); and U.S. Pat. Nos. 5,591,616 and 5,679,558 (Rice).

Vectors can include such items as: leader sequences, transit polypeptides, promoters, terminators, genes, introns, marker genes, etc. The structures of the gene orientations can be sense, antisense, partial antisense, or partial sense: multiple gene copies can be used. The transgenic gene can come from various non-plant genes (such as; bacteria, yeast, animals, and viruses) along with being from plants.

The DNA is then transformed into the plant. A transgene introgressed into this invention typically comprises a nucleotide sequence whose expression is responsible or contributes to the trait under the control of a promoter appropriate for the expression of the nucleotide sequence at the desired time in the desired tissue or part of the plant. Constitutive or inducible promoters are used. The transgene may also comprise other regulatory elements such as for example translation enhancers or termination signals. In an embodiment, the nucleotide sequence is the coding sequence of a gene and is transcribed and translated into a protein. In another embodiment, the nucleotide sequence encodes an antisense RNA, a sense RNA that is not translated or only partially translated, a t-RNA, a r-RNA or a sn-RNA.

Where more than one trait is introgressed into this invention, it is that the specific genes are all located at the same genomic locus in the donor, non-recurrent parent, preferably, in the case of transgenes, as part of a single DNA construct integrated into the donor's genome. Alternatively, if the genes are located at different genomic loci in the donor, non-recurrent parent, backcrossing allows to recover all of the morphological and physiological characteristics of the invention in addition to the multiple genes in the resulting maize inbred line.

In an embodiment, a transgene whose expression results or contributes to a desired trait to be transferred to the present invention comprises a virus resistance trait such as, for example, a MDMV strain B coat protein gene whose expression confers resistance to mixed infections of maize dwarf mosaic virus and maize chlorotic mottle virus in transgenic maize plants (Murry et al. Biotechnology (1993) 11:1559 64). In another embodiment, a transgene comprises a gene encoding an insecticidal protein, such as, for example, a crystal protein of Bacillus thuringiensis or a vegetative insecticidal protein from Bacillus cereus, such as VIP3 (see for example, Estruch et al. Nat Biotechnol (1997) 15:137 41). Also see, U.S. Pat. Nos. 5,877,012, 6,291,156; 6,107,279 6,291,156 and 6,429,360. In another embodiment, an insecticidal gene introduced into present invention is a Cry1Ab gene or a portion thereof, for example, introgressed into present invention from a maize line comprising a Bt-11 event as described in U.S. Pat. No. 6,114,608, which is incorporated herein by reference, or from a maize line comprising a 176 event as described in Koziel et al. (1993) Biotechnology 11: 194 200. In yet another embodiment, a transgene introgressed into present invention comprises a herbicide tolerance gene, for example, that is resistant to dicamba or a tolerance gene which provides of an altered acetohydroxyacid synthase (AHAS) enzyme confers upon plants tolerance to various imidazolinone or sulfonamide herbicides (U.S. Pat. No. 4,761,373). In another embodiment, a non-transgenic trait conferring tolerance to imidazolinones is introgressed into present invention (e.g. a “IT” or “IR” trait). U.S. Pat. No. 4,975,374, incorporated herein by reference, relates to plant cells and plants containing a gene encoding a mutant glutamine synthetase (GS) resistant to inhibition by herbicides that are known to inhibit GS, e.g. phosphinothricin and methionine sulfoximine. Also, expression of a Streptomyces bar gene encoding a phosphinothricin acetyl transferase in maize plants results in tolerance to the herbicide phosphinothricin or glufosinate (U.S. Pat. No. 5,489,520). U.S. Pat. No. 5,013,659, which is incorporated herein by reference, is directed to plants that express a mutant acetolactate synthase (ALS) that renders the plants resistant to inhibition by sulfonylurea herbicides. U.S. Pat. No. 5,162,602 discloses plants tolerant to inhibition by cyclohexanedione and aryloxyphenoxypropanoic acid herbicides. The tolerance is conferred by an altered acetyl coenzyme A carboxylase (ACCase). U.S. Pat. No. 5,554,798 discloses transgenic glyphosate tolerant maize plants, which tolerance is conferred by an altered 5-enolpyruvyl-3-phosphoshikimate (EPSP) synthase gene. U.S. Pat. No. 5,804,425 discloses transgenic glyphosate tolerant maize plants, which tolerance is conferred by an EPSP synthase gene derived from Agrobacterium tumefaciens CP-4 strain. Also, tolerance to a protoporphyrinogen oxidase inhibitor is achieved by expression of a tolerant protoporphyrinogen oxidase enzyme in plants (U.S. Pat. No. 5,767,373). Another trait transferable to the present invention confers a safening effect or additional tolerance to an inhibitor of the enzyme hydroxyphenylpyruvate dioxygenase (HPPD) and transgenes conferring such trait are, for example, described in WO 9638567, WO 9802562, WO 9923886, WO 9925842, WO 9749816, WO 9804685 and WO 9904021. All issued patents referred to herein are, in their entirety, expressly incorporated herein by reference.

In an embodiment, a transgene transferred to present invention comprises a gene conferring tolerance to a herbicide and at least another nucleotide sequence encoding another trait, such as for example, an insecticidal protein. Such combination of single gene traits is, for example, a Cry1Ab gene and a bar gene. The introgression of a Bt11 event into a maize line, such as present invention, by backcrossing is exemplified in U.S. Pat. No. 6,114,608, and the present invention is directed to methods of introgressing a Bt11 event into present invention and to progeny thereof using for example the markers described in U.S. Pat. No. 6,114,608.

By way of example only, specific events (followed by their APHIS petition numbers) that can be introgressed into maize plants by backcross breeding techniques include the glyphosate tolerant event GA21 (97-09901p) or the glyphosate tolerant event NK603 (00-011-01p), the glyphosate tolerant/Lepidopteran insect resistant event MON 802 (96-31701p) Mon810, Lepidopteran insect resistant event DBT418 (96-29101p), male sterile event MS3 (95-22801p), Lepidopteran insect resistant event Bt11 (95-19501p), phosphinothricin tolerant event B16 (95-14501p), Lepidopteran insect resistant event MON 80100 (95-09301p) and MON 863 (01-137-01p), phosphinothricin tolerant events T14, T25 (94-35701p), Lepidopteran insect resistant event 176 (94-31901p), Western corn rootworm (04-362-01p), the phosphinothricin tolerant and Lepidopteran insect resistant event CBH-351 (92-265-01p), and the transgenic corn event designated 3272 taught in US application publication 20060230473 (hereby incorporated by reference).

A further subject of the present invention is the plants which comprise transformed cells, in particular the plants regenerated from transformed cells. Regeneration is effected by any suitable process, which depends on the nature of the species as described, for example, in the references hereinabove. Patents and patent applications which are cited in particular for the processes for transforming plant cells and regenerating plants are the following: U.S. Pat. Nos. 4,459,355, 4,536,475, 5,464,763, 5,177,010, 5,187,073, EP 267,159, EP 604 662, EP 672 752, U.S. Pat. Nos. 4,945,050, 5,036,006, 5,100,792, 5,371,014, 5,478,744, 5,179,022, 5,565,346, 5,484,956, 5,508,468, 5,538,877, 5,554,798, 5,489,520, 5,510,318, 5,204,253, 5,405,765, EP 442 174, EP 486 233, EP 486 234, EP 539 563, EP 674 725, WO 91/02071 and WO 95/06128.

The use of pollen, cotyledons, zygotic embryos, meristems and ovum as the target tissue can eliminate the need for extensive tissue culture work. Generally, cells derived from meristematic tissue are useful. The method of transformation of meristematic cells of cereal is taught in the PCT application WO96/04392. Any number of various cell lines, tissues, calli and plant parts can and have been transformed by those having knowledge in the art. Methods of preparing callus or protoplasts from various plants are well known in the art and specific methods are detailed in patents and references used by those skilled in the art. Cultures can be initiated from most of the above-identified tissue. The only true requirement of the transforming plant material is that it can ultimately be used to form a transformed plant.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322 332 reflects that 97% of the plants cultured that produced callus were capable of plant regeneration. Subsequent experiments with both inbreds and hybrids produced 91% regenerable callus that produced plants. In a further study in 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988), 7:262 265 reports several media additions that enhance regenerability of callus of two inbred lines. Other published reports also indicated that “nontraditional” tissues are capable of producing somatic embryogenesis and plant regeneration. K. P. Rao, et al., Maize Genetics Cooperation Newsletter, 60:64 65 (1986), refers to somatic embryogenesis from glume callus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345 347 (1987) indicates somatic embryogenesis from the tissue cultures of maize leaf segments. Thus, it is clear from the literature that the state of the art is such that these methods of obtaining plants are, and were, “conventional” in the sense that they are routinely used and have a very high rate of success.

Tissue culture procedures of maize are described in Green and Rhodes, “Plant Regeneration in Tissue Culture of Maize,” Maize for Biological Research (Plant Molecular Biology Association, Charlottesville, Va. 1982, at 367 372) and in Duncan, et al., “The Production of Callus Capable of Plant Regeneration from Immature Embryos of Numerous Zea mays Genotypes,” 165 Planta 322 332 (1985). Thus, another aspect of this invention is to provide cells that upon growth and differentiation produce maize plants having the physiological and morphological characteristics of the present invention.

Maize is used as human food, livestock feed, and as raw material in industry. Sweet corn kernels having a relative moisture of approximately 72% are consumed by humans and may be processed by canning or freezing. The food uses of maize, in addition to human consumption of maize kernels, include both products of dry- and wet-milling industries. The principal products of maize dry milling are grits, meal and flour. The maize wet-milling industry can provide maize starch, maize syrups, and dextrose for food use. Maize oil is recovered from maize germ, which is a by-product of both dry- and wet-milling industries.

The present invention encompasses a method of producing treated hybrid or inbred seed of the present invention and the resultant treated seed. The method includes obtaining seed and treating the seed to improve its performance. Hybrid and inbred seed is often treated with one or more pesticides including fungicides, herbicides, herbicidal safeners, fertilizers, insecticides, acaricides, nematocides, bactericides, virus resistant material and other biocontrol agents. Pyrethrins, synthetic pyrethroids, oxadizine derivatives, chloronicotinyls, nitroguanidine derivatives and triazoles, organophosphates, pyrrols, pyrazoles, phenyl pyrazoles, diacylhydrazines, biological/fermentation products and carbamates are used as pesticidal seed treatments. Additionally, Fludioxonil, mefenoxam, azoxystrobin, thiamethoxam, clothianidin and the like are frequently used to treat maize seed. Methods for treating seed using fluidized beds, roller mills, rotostatic seed treater and drum coaster, misting, soaking, filming coating and the like. These methods of seed treatment are well known in the industry. The present invention encompasses a hybrid plant with a plant part being the segregating grain formed on the ear of the hybrid. This grain is a commodity plant product as are the protein concentrate, protein isolate, starch, meal, flour or oil. A number of different industrial processes extract or utilize these plant products.

Maize, including both grain and non-grain portions of the plant, is also used extensively as livestock feed, primarily for beef cattle, dairy cattle, hogs, and poultry. Industrial uses of maize include production of ethanol, maize starch in the wet-milling industry and maize flour in the dry-milling industry. The industrial applications of maize starch and flour are based on functional properties, such as viscosity, film formation, adhesive properties, and ability to suspend particles. The maize starch and flour have application in the paper and textile industries. Other industrial uses include applications in adhesives, building materials, foundry binders, laundry starches, explosives, oil-well muds, and other mining applications. Plant parts other than the grain of maize are also used in industry: for example, stalks and husks are made into paper and wallboard and cobs are used for fuel and to make charcoal.

The seed of the present invention or of the present invention further comprising one or more single gene traits, the plant produced from the inbred seed, the hybrid maize plant produced from the crossing of the inbred, hybrid seed and various parts of the hybrid maize plant, can be utilized for human food, livestock feed, and as a raw material in industry.

The present invention therefore also discloses an agricultural product comprising a plant of the present invention or derived from a plant of the present invention. The present invention also discloses an industrial product comprising a plant of the present invention or derived from a plant of the present invention. The present invention further discloses methods of producing an agricultural or industrial product comprising planting seeds of the present invention, growing plant from such seeds, harvesting the plants and processing them to obtain an agricultural or industrial product.

A deposit of at least 2500 seeds of this invention will be maintained by Syngenta Seeds Inc. Access to this deposit will be available during the pendency of this application to the Commissioner of Patents and Trademarks and persons determined by the Commissioner to be entitled thereto upon request. All restrictions on availability to the public of such material will be removed upon issuance of a granted patent of this application by depositing at least 2500 seeds of this invention at the American Type Culture Collection (ATCC), at 10801 University Boulevard, Manassas, Va. 20110. The date of deposit was Dec. 22, 2010. The seed deposit, labelled as ATCC Accession Number PTA-11566, was tested and found to be viable on Jan. 11, 2011. The deposit of at least 2500 seeds will be from inbred seed taken from the deposit maintained by Syngenta Seeds Inc. The ATCC deposit will be maintained in that depository, which is a public depository, for a period of 30 years, or 5 years after the last request, or for the enforceable life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period.

Additional public information on patent variety protection may be available from the PVP Office, a division of the U.S. Government.

NPXO5745GT21

Variety Description Information

Region Best Adapted: —Broadly Adapted

*MG **Maturity Hybrid Group Range RM*** (estimate) 5 103-107 107 *MG = Maturity group **Maturity is the number of days from planting to physiological maturity (planting to black layer) ***RM = relative maturity

1. TYPE: 05 1 = Flint  2 = Flint-like  3 = Intermediate  4 = Dent-like  5 = Dent 2. MATUR ITY (In Region Best Adaptability. show Heat Unit Formula in Comment section): DAYS HEAT UNI TS 067 1369.5 From planting to 50% of plants in silk 068 1394.0 From planting to 50% of plants in pollen 3. PLANT: Standard Deviation Sample Size 213.2 cm Plant Height (to tassel tip) 6.4 15 063.9 cm Ear Height (to base of top ear node) 6.9 15 016.7 cm Length of Top Ear Internode 1.1 15 3 Anthocyanin of Brace Roots (when brace roots are green with some red or purple anthocyanin in stripes or speckles, rate the shade of anthocyanin) 1 = Absent (Green) 3 = Weak (Pink) 5 = Medium (Light red; Light red/purple) 7 = Strong (Red; Red/purple) 9 = Very Strong (Dark red/purple) 4. LEAF: Standard Deviation Sample Size 009.3 cm Width of Ear Node Leaf 0.7 15 069.9 cm Length of Ear Node Leaf 3.6 15 1 Leaf Attitude from main stem to tip of leaf (see UPOV diagrams) 1 = Erect  3 = Horizontal  5 = Drooping 5 Pubescence on margin/edge of leaf sheath (Rate on scale from 1 = none to 9 = like peach fuzz) 5. TASSEL Standard Deviation Sample Size 03 Number of Primary Lateral Branches 0.9 15 37.3 cm Tassel Length (From top node 2.4 15 below flag leaf to tassel tip) 5.6 cm Tassel Peduncle Length (From top 1.8 15 node below flag leaf to bottom tassel branch) 23.7 cm Tassel Central Spike Length 2.3 15 (From top tassel branch to tassel tip) 1 Branch Altitude from Central Spike from main spike to tip of tassel branch (see UPOV diagrams) 1 = Erect 3 = Horizontal 5 = Drooping 1 Anther Color (2-3 days after being exposed to allow for sun reddening effects) 2.5Y7/4 1= Green or Yelow (ex. Munsell Code 2.5GY8/6 or 10Y8.5/6) 3 = Pink (ex. Munsell 2.5R 7/6 or 5R 5/6) 5 = Red (ex. Munsell 2.5R 4/8) 7 = Dark Red (ex. Munsell 10RP 4/8) 9 = Purple (ex. Munsell 5RP 5/8 ) 1 Glume Color (on the top 2/6 of the glume) 5GY7/6 1 = Green or Yellow (ex. Munsell Code 2.5GY 8/6 or 10Y 8.5/6) 3 = Pink (ex. Munsell 2.5R 7/6 or 5R 5/6) 5 = Red (ex. Munsell 2.5R 4/8) 7 = Dark Red (ex. Munsell 10RP 4/8) 9 = Purple (ex. Munsell 5RP 5/8) 3 Bar Glume Anthocyanin Color (on the bottom 1/3 of glume; see UPOV Diagram; Note: the bar glume is listed as “present” if it is present and the ring is at least 50% closed) 5R5/6 1 = Green or Yelow (ex. Munsell Code 2.5GY 8/6 or 10Y8.5/6) 3 = Pink (ex. Munsell 2.5R 7/6 or 5R 5/6) 5 = Red (ex. Munsell 2.5R 4/6) 7 = Dark Red (ex. Munsell 10RP 4/8) 9 = Purple (ex Munsell 5RP 5/8) 6a. EAR (Unhusked Data) Standard Deviation Sample Size 5.4 cm Husk Extension (at harvest) 0.8 15 21.0 cm Husk Leaf Length 0.6 15 1 Silk Color (2-3 days after emergence to allow for sun reddening effects) 2.5GY8/6 1 = Green or Yellow (ex. Munsell Code 2.5GY 8/6 or 10Y 8.5/6 3 = Pink (ex. Munsell 2.5R 7.6 or 5R 5/6) 5 = Red (ex. Munsell 2.5R 4/8) 7 = Dark Red (ex. Munsell 10RP 4/6) 9 = Purple (ex. Munsell 5RP 5/8) 6b. EAR (Husked Ear Data): Standard Deviation Sample Size 15.5 cm Ear Length 0.9 15 43.3 mm Ear Diameter at mid-pint 1.4 15 139.6 gm Ear Weight 7.8 15 16 Number of Kernel Rows 1.3 15 30.2 Numher of Kernels per Row 2.6 5 08.2 an Shank Length 0.7 15 7. KERNEL (Dried): Standard Deviation Sample Size 11.1 mm Kernel Length 0.6 15 07.4 mm Kernel Width 0.4 16 2 Hard Endosperm Color 2.5Y7/10 1= White (ex. Munsell Code 5Y9/1 or 2.5Y8.5/2) 2 = Yellow (ex. Munsell Code 2.5Y8/10 or 7.5YR 7/14) 3 = Other (specify _____________) 1 Endosmnn Type: 1 = Normal Starch 2 = High Arnylose Statch 3 = Waxy Starch 4 = High Protein 5 = High Lysine 6 = High Oil 7 = Other _____________ 23.7 gm Weight per 100 Kernels (unsized sample) 0.3  5 8. COB: Standard Deviation Sample Size 24.1 mm Cob Diameter at mid-point 1.2 15 4 Cob Color 2.5YR4/6 1 = White (ex. Munsell 5Y 9/1 or 2.5Y 8.5/2) 2 = Pink (ex. Munsell 2.5R 7/6 or 5R 5/6) 3 = Red (ex. Munsell 2.5R 4/8 or 10RP 4/6) 4 = Other (describe  Reddish Brown) 9. DISEASE RESISTANCE of the variety per se: Name the disease, the causative organism the races or strains, and the resistance rating (rate from 1 (most susceptible) to 9 (most resistant). Trials should be conducted with resistant and susceptible check varieties, and ensure that adequate disease pressure is present in the trial (such as with inoculations or heavy disease pressure). EXAMPLE: 7  Helminthosporlun Leaf Spot (bipolaris zeicola)  Race 2 5 Eyespot (Kabatiella zeae) 7 Gray Leaf Spot (Cercospora zeae-maydis) 6 Southern Leaf Blight (Bipolaris maydis) 5 Goss's Wilt (Clavibacter michiganense spp. nebrsakense) 10. INSECT RESISTANCE of the variety per se: Name the insect, give its scientific name, and the resistance rating (rate from 1 (most susceptible) to 9 (most resistant). Trials should be conducted with resistant and susceptible check varieties, and ensure that adequate insect pressure is present in the trial (such as with inoculations or heavy insect pressure). EXAMPLE: European Corn Borer (Ostrinia nubilatis) 7 1st Generation (Typically Whorl Leaf feeding)

The purity and homozygosity of inbred NPXO5745GT21 is constantly being tracked using isozyme genotypes. Isozyme data can be generated for inbred corn line NPXO5745GT21 according to procedures known and published in the art.

Isozyme Genotypes for NPXO5745GT21

Isozyme data were generated for inbred corn line NPXO5745GT21 according to procedures known and published in the art. The data in the Electrophoresis Table gives the electrophoresis data on NPXO5745GT21.

ELECTROPHORESIS RESULTS FOR NPXO5745GT21 Line PGM1 PGM2 PGD1 PGD2 IDH1 IDH2 MDH1 MDH2 MDH3 MDH4 MDH5 NPXO5745 9 4 2 5 4 6 6 6 16 Mm GT21 Inbred1 9 4 2 5 4 6 6 6 16 Mm Inbred2 9 4 2 5 4 6 6 6 16 Mm Line MDH6 ACP1 ACP4 GLU PHI CAT3 DIA1 GOT1 GOT2 GOT3 ADH NPXO5745 2 4 4 4 GT21 Inbred1 2 4 4 4 Inbred2 4 4 4 4

The Paired Inbred Comparison Data Table shows a comparison between NPXO5745GT21 and two comparable inbreds. The isozymes do not distinguish the differences between these lines.

In the Paired Inbred Comparison Data Table NPXO5745GT21 is has significantly more large round seed sizes and less medium round seed than does the comparable inbred 1.

PAIRED INBRED COMPARISON DATA TABLE Inbred Yield Stand HeatUnits to P50 HeatUnits to S50 Plant Height Ear Height NPXO5745GT21 75.2 34285.7 1380.2 1411.5 Inbred1 73.8 35549.3 1378.1 1412.7 Diff 1.5 1263.6 2.1 1.2 # Expts 7 7 13 13 Prob 0.782 0.406 0.702 0.846 % Large % Large % Med. % Med. % Small % Small Inbred Rounds Flats Rounds Flats Rounds Flats NPXO5745GT21 15.6 2.7 3.1 1.4 26.2 44.9 Inbred1 1.8 1.4 10.9 5.7 49.9 29.2 Diff 13.9 1.3 7.8 4.3 23.7 15.7 # Expts 7 7 7 7 7 7 Prob 0.000*** 0.011** 0.001*** 0.001*** 0.000*** 0.001*** *.05 < Prob <= .10 **.01 < Prob <= .05 ***.00 < Prob <= .01

The General Combining Ability Table shows the GCA (General Combining Ability) estimates of NPXO5745GT21 compared with the GCA estimates of the other inbreds. The estimates show the general combining ability is weighted by the number of experiment/location combinations in which the specific hybrid combination occurs. The interpretation of the data for all traits is that a positive comparison is a practical advantage. A negative comparison is a practical disadvantage. The general combining ability of an inbred is clearly evidenced by the results of the general combining ability estimates. This data compares the inbred parent in a number of hybrid combinations to a group of “checks”. The check data is from our company's and other companies' hybrids which are commercial products and pre-commercial hybrids, which were grown in the same sets and locations.

General Combining Ability Table % % % Late % Early Line in hybrid Test Stalk Push Root Root combination N Yield Moisture Weight Lodging Test Lodging Lodging NPXO5745GT21 58 −3.83 −1.15 −0.59 0.53 11.69 6.5 5.2 NPXO5745GT21 49 — 0.44 1.31 0.3 1.08 0.59 3.09 NPXO5745GT21 19 −17.5 −0.17 −2.86 0.55 5 NPXO5745GT21 58 −2.08 −0.96 −0.98 0.99 13.33 3.43 4.65 NPXO5745GT21 67 −2.06 −1.43 −1.16 −0.13 15.51 1.71 0.78 XR = 25 −6.35 −0.79 −0.56 0.41 11.52 3.56 3.72 XH = 5 −8.28 −0.65 −0.85 0.45 10.4 3.45 3.43 XT = % Stay % Line in hybrid Dropped Final Green Green % Emergence combination N Ears Stand % Snap Barren Rating NPXO5745GT21 58 0 −1.4 20 −2.73 −0.11 0.18 NPXO5745GT21 49 0 −5.96 20 −2.83 0.08 0.13 NPXO5745GT21 19 −1.64 9.56 −0.8 NPXO5745GT21 58 0 −8.17 17.5 −4.03 −0.95 0.29 NPXO5745GT21 67 −0.07 −1.04 23.75 −0.01 −0.31 −0.18 XR = 251 −0.03 −3.78 20.08 −1.8 −0.45 0.1 XH = 5 −0.02 −3.64 20.31 −0.01 −0.42 0.1 XT = Line in hybrid Vigor Heatunits Heatunits Ear Plant combination N Rating to S50 to P50 Height Height NPXO5745GT21 58 0.24 41.38 47.19 −5.46 −5.51 NPXO5745GT21 49 0.29 2.13 7.94 −1.41 3.86 NPXO5745GT21 19 12 −35.5 −2.66 −8.48 NPXO5745GT21 58 −0.04 2.13 7.94 0.34 −4.55 NPXO5745GT21 67 0.18 −36.25 −37.33 −9.13 −1.14 XR = 251 0.17 −0.55 −2.14 −3.92 −2.87 XH = 5 0.17 4.28 −1.95 −3.67 −3.16 XT = XR = GCA Estimate: Weighted by Expt XH = GCA Estimate: Weighted by Parent2 XT = Same as XH but using only those parent2 with two years of data

The Paired Hybrid Comparison Data Table A shows the inbred NPXO5745GT21 in hybrid combination, as Hybrid 1, in comparison with another hybrid, which is adapted for the same region of the Corn Belt. When in hybrid combination with the present inbred NPXO5745GT21 (designated Hybrid 1) carries significantly less moisture. In addition, the present invention evidences an ability to use water efficiently.

PAIRED HYBRID COMPARISON DATA TABLE PCTER POTS PCTPUS PLTLR PCTD Hybrid Yield Moist TWT L L H L E Hybrid 1 155.4 16.7 52.9 0.9 30 w/NPXO5745GT21 Hybrid2 167.6 17.4 52.6 1.8 55 # Expts 38 38 24 6 2 Diff 12.2 0.7 0.3 0.8 25 Prob 0.006** * 0.029** 0.364 0.571 0.344 Hybrid Stand PCTSG PCTGS PctBarren Emerge Vigor HUS50 Hybrid1 w/NPXO5745GT21 56.3 13.2 1 1257 Hybrid2 57.2 11.8 1.2 1244 # Expts 38 2 12 2 Diff 0.9 1.5 0.2 12.5 Prob 0.037** 0.66 0.5 Hybrid HUP50 Pltht Earht Hybrid1 w/NPXO5745GT21 1197 231.9 112.1 Hybrid2 1221 236.4 111.3 # Expts 2 8 8 Diff 24 4.6 0.8 Prob 0.399 0.87 *.05 < Prob <= .10 **.01 < Prob <= .05 ***.00 < Prob <= .01

The Yield by Environment Response Table shows the yield response of Hybrid 1 w/NPXO5745GT21 (with the present invention as a parent in the hybrid) when compared to another hybrids and the plants in the environment around it at the same location. The data for the present inbred is showing a yield which is within the error of 23.4 and the environment level of yield.

Yield By Environment Response Table Research Plots 75 100 125 150 175 200 Hybrid Error # Plots Environment Yield Hybrid1 w/NPXO5745GT21 23.4 19 76 98 119 140 162 183 Hybrid2 15.9 97 73 100 127 154 182 209

Accordingly, the present invention has been described with some degree of particularity directed to the embodiment of the present invention. It should be appreciated, though that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the embodiment of the present invention without departing from the inventive concepts contained herein. 

We claim:
 1. A seed of the maize inbred plant NPXO5745GT21, representative seed of said plant having been deposited under ATCC Accession Number PTA-11566.
 2. A maize inbred plant NPXO5745GT21, representative seed of said NPXO5745GT21 plant having been deposited under ATCC Accession Number PTA-11566.
 3. A plant part of the plant of claim
 2. 4. The plant part of claim 3, wherein said part is pollen, protoplast, cell, tassel, anther or an ovule.
 5. A maize seed comprising the plant part of claim 3, said plant part is a cell.
 6. A process for producing an F1 hybrid maize seed, said process comprising crossing the maize inbred plant NPXO5745GT21 according to claim 2 with a different maize plant and harvesting the resultant F1 hybrid maize seed.
 7. An F1 hybrid maize seed comprising an inbred maize plant cell of the inbred maize plant NPXO5745GT21 according to claim 2, representative seed of said plant having been deposited under ATCC Accession Number PTA-11566.
 8. A maize plant or part thereof produced by growing the F1 hybrid maize seed of claim
 7. 9. A method for producing maize seed comprising growing the plant of claim 2 until seed is produced, harvesting the seed, wherein the harvested seed is inbred or hybrid or haploid seed.
 10. A seed produced by the method of claim
 9. 11. A process of introducing a desired trait into maize inbred plant NPXO5745GT21 comprising: (a) crossing NPXO5745GT21 plants grown from NPXO5745GT21 seed, representative seed of which has been deposited under ATCC Accession Number PTA-11566, with plants of another maize plant that comprise a desired trait to produce F1 progeny plants, wherein the desired trait is selected from the group consisting of waxy starch, male sterility, herbicide resistance, altered starch, insect resistance, bacterial disease resistance, fungal disease resistance, and viral disease resistance; (b) selecting F1 progeny plants that have the desired trait to produce selected F1 progeny plants; (c) crossing the selected progeny plants with the NPXO5745GT21 plants to produce backcross progeny plants; (d) selecting for backcross progeny plants that have the desired trait to produce selected backcross progeny plants; and (e) repeating steps (c) and (d) at least three or more times to produce backcross progeny plants that comprise the desired trait and all of the physiological and morphological characteristics of maize inbred plant NPXO5745GT21 listed in Table 1 when grown in the same environmental conditions.
 12. A plant produced by the process of claim
 11. 13. A maize plant having all the physiological and morphological characteristics of inbred plant NPXO5745GT21 wherein, a sample of the seed of inbred plant NPXO5745GT21 was deposited under ATCC Accession Number PTA-11566.
 14. The maize plant of claim 13, comprising a genome which further comprises at least one transgene, or further exhibiting a trait conferred by the transgene.
 15. The maize plant of claim 14, wherein the transgene confers a trait selected from the group consisting of herbicide tolerance; insect tolerance; resistance to bacterial, fungal, nematode or viral disease; waxy starch; altered starch, male sterility or restoration of male fertility, modified carbohydrate metabolism and modified fatty acid metabolism.
 16. A method of producing a corn plant derived from the variety NPXO5745GT21, the method comprising the steps of (a) growing a progeny plant produced by crossing the plant of claim 2 with a second corn plant; (b) crossing the progeny plant with itself or a different plant to produce a seed of a next progeny plant of a subsequent generation; (c) growing said next progeny plant of a subsequent generation and crossing the next progeny plant of a subsequent generation with itself or a different plant; and (d) repeating growing and crossing steps in step (c) for an additional 0-5 generations to produce a corn plant derived from the variety NPXO5745GT21.
 17. A method for developing a maize plant in a maize plant breeding program, comprising applying plant breeding techniques comprising recurrent selection, backcrossing, pedigree breeding, marker enhanced selection, haploid/dihaploid production, or transformation to the maize plant of claim 2, or its parts, wherein application of said techniques results in development of a maize plant.
 18. A method of producing a commodity plant product comprising growing a plant from the seed of claim 10 or a part thereof and producing said commodity plant product comprising protein concentrate, protein isolate, starch, meal, flour or oil therefrom.
 19. A method of producing a treated seed of claim 10 comprising obtaining the seed of NPXO5745GT21 and treating said seed.
 20. A maize seed produced by crossing the plant of claim 2 with a different maize plant. 